Yes Aisha you are correct, the Arduino works with 5V and the MSP430G2 typically works with 3.3V. So we cannot directly connect a 5V sensor to the ADC pins of MSP430.

The maximum voltage that could be applied to the ADC pin of MSP430 is equal to the operating voltage of the MSP430 board. The maximum operating voltage of MSP430G2 is only 4.1V so there is no way we can read upto 5V. uisng this board.

The best way to go around this is to use a potential divider, this will map the 0-5V from the sensor to 0-3.3V ofcourse the resolution will be lost. But I cant think of a simpler way. If you are very concerned about resolution then use an external ADC.

You can calculate the value for resistor from this calculator it also explains the connections. Roughly the values should be 1K and 2K for converting 5V to 3.3V.